/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.util;

/**
 * This StringMatcher tests whether strings start with a specified variable string and then match another optional given
 * StringMatcher.
 *
 * @see VariableStringMatcher
 * @author Eric Lafortune
 */
public class MatchedStringMatcher extends StringMatcher {
    private final VariableStringMatcher variableStringMatcher;
    private final StringMatcher nextMatcher;

    /**
     * Creates a new MatchedStringMatcher
     *
     * @param variableStringMatcher the variable string matcher that can provide the string to match.
     * @param nextMatcher an optional string matcher to match the remainder of the string.
     */
    public MatchedStringMatcher(VariableStringMatcher variableStringMatcher, StringMatcher nextMatcher) {
        this.variableStringMatcher = variableStringMatcher;
        this.nextMatcher = nextMatcher;
    }

    // Implementation for StringMatcher.

    @Override
    protected boolean matches(String string, int beginOffset, int endOffset) {
        String matchingString = variableStringMatcher.getMatchingString();
        if (matchingString == null) {
            return false;
        }

        int stringLength = endOffset - beginOffset;
        int matchngStringLength = matchingString.length();
        return stringLength >= matchngStringLength && string.startsWith(matchingString, beginOffset)
            && ((nextMatcher == null && stringLength == matchngStringLength)
                || nextMatcher.matches(string, beginOffset + matchngStringLength, endOffset));
    }
}
